Control circuits may be used to control the amount of current flowing through loads with specific current and/or voltage requirements, such as chains of light-emitting diodes (LEDs). The light intensity of an LED chain is controlled by the amount of current flowing through it. Generally, a closed loop current generator may be used to keep the current constant. For lighting with a high current load, switched-mode controllers may be used. In applications that demand high efficiency and high flexibility, such as in some automotive lighting applications, buck, boost, or buck-boost DC/DC converter topologies may be used. Some applications in automotive lighting or other applications involve multiple LED chains connected in parallel. The number may vary depending on the specific application. One or more of the LED chains can be switched on or off at times (e.g. connected or disconnected from the circuit). This change in the number of LED chains means the constant current may sink through fewer or additional chains. A control circuit may control the current flowing through the LED chain or chains as different numbers of the chains are connected or disconnected.